Integrating Other Functions (Cambridge (CIE) A Level Maths: Pure 3): Revision Note

Exam code: 9709

Amber

Written by: Amber

Reviewed by: Dan Finlay

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Integrating other functions

Is integration the reverse of differentiation?

  • Yes, but remember “+c”, the constant of integration …

    • … unless finding a definite integral

  • Recognising common results helps to make integration easier

    (See Differentiating Other Functions)

  

  • You are given all the standard integrals in the formula booklet

 

Notes diff_results, AS & A Level Maths revision notes

How do I integrate ex and ekx?

Notes ex, AS & A Level Maths revision notes

 

  • The gradient of ekx is kekx

    • ie y = ekx, dy/dx = kekx

  • The reverse applies when integrating

  • This is an example of reverse chain rule

 

Notes ekx, AS & A Level Maths revision notes

How do I integrating 1/x?

Notes ln, AS & A Level Maths revision notes

 

  • Remember 1/x = x-1

    • The method for integrating powers does not apply if the power is -1

 

How do I integrating sin x and cos x?

Notes sin_cos, AS & A Level Maths revision notes

 

  • Note the minus in the integral of sin x

How do I integrate tan x?

  • The integral of tan x is ln|sec x| + c

How do I integrate fraction numerator 1 over denominator 1 space plus space x squared end fraction and fraction numerator 1 over denominator a squared space plus space x squared end fraction?

  • Recall that fraction numerator straight d over denominator straight d x end fraction left parenthesis tan to the power of negative 1 end exponent x right parenthesis space equals space fraction numerator 1 over denominator 1 space plus space x squared end fraction

  • Then integral fraction numerator 1 over denominator 1 space plus space x squared end fraction space straight d x space equals space tan to the power of negative 1 end exponent x space plus space c and integral fraction numerator 1 over denominator a squared space plus space x squared end fraction space straight d x space equals space 1 over a tan to the power of negative 1 end exponent open parentheses x over a close parentheses space plus space c

Examiner Tips and Tricks

  • Make sure you have a copy of the formula booklet during revision but don't try to remember everything in the formula booklet.

  • However, do be familiar with the layout of the formula booklet – you’ll be able to locate quickly whatever you are after, and you do not want to be searching every line of every page!

  • For formulae you think you have remembered, use the booklet to double-check.

Worked Example

Example soltn(a), AS & A Level Maths revision notes
Example soltn(b), AS & A Level Maths revision notes
Example soltn(c), AS & A Level Maths revision notes


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Amber

Author: Amber

Expertise: Maths Content Creator

Amber gained a first class degree in Mathematics & Meteorology from the University of Reading before training to become a teacher. She is passionate about teaching, having spent 8 years teaching GCSE and A Level Mathematics both in the UK and internationally. Amber loves creating bright and informative resources to help students reach their potential.

Dan Finlay

Reviewer: Dan Finlay

Expertise: Portfolio Lead

Dan graduated from the University of Oxford with a First class degree in mathematics. As well as teaching maths for over 8 years, Dan has marked a range of exams for Edexcel, tutored students and taught A Level Accounting. Dan has a keen interest in statistics and probability and their real-life applications.